Method of and apparatus for uniting plastic material



May 29, 1945.

C. W. LEGUILLQN ETAL HMETHOD OF AND APPARATUS -FOR UNITING PLASTICMATERIAL Filed June 27, 1941 i' 27 E17/bas 7J-'4 baE/Es v2/".55 U17/anpatented ay 29, 1945 i amis METHOD F AND APPARATUS FOR UNITING PLASTICMATERIAL Charles W. Leguillon and Harvey L. Young, Akron, Ohio,asslgnors to The B. F. Goodrich Company,

New York, N. Y., a corporation or New York Application June 27, 19M,Serial No. @106,074

' 12 Claims.

This invention relates to the manufacture of rubber-like plasticmaterial in strip form, including slabs, strips and sheets, and is'especially useful in the manufacture of composite tread slabs for tires.

Heretofore, where tread material for pneumatic tires has been assembledby bringing slab portions of extruded or calendered rubber together insu-a perimposed relation, in Athe use of the tires built of such slabmaterial, cracking of the slabs has sometimes occurred along the edgesof the outermost slab portion, especially where the materials of theadjoining portions have been of different compositions or where dust ormoisture has been permitted to enter the joint before vulcanization hastaken place. A

The principaly objects of the invention are to provide a uniformcomposite slab or other strip free from cracks, to provide a comminglingof dierent stocks to bond them tov each other permanently, to provideeffective sealing at margins, and to provide improved apparatus andprocedure for assembling layers of slab material.

These and other objects will appear from the following description andthe accompanying drawing.

0i the drawing: l

Fig. 1 is a cross-sectional view of a slab-assembling apparatusconstructed according t0 and embodying the invention, parts being brokenaway.

Fig, A2 is a longitudinal sectional view of the apparatus, taken alongline 2-2'of Fig. 1.

Fig. 3 is a detail view showing an adjusting mechanism.

Fig. 4 is a detail sectional view taken along line 4--4 oi Fig. 1. A

Fig. 5 is a detail view, partly in section, of a pressure roller takenalong the line 5 5 of Fig. 2.

Fig. 6 is an enlarged detail view of an edge of the slab and a puddlertool acting thereagainst.

In accordance with `the invention adjoining bodies or portions. ofrubber-like plastic material in superimposed relation are advanced topresent the margins of their `ioint progressively to means for effectinga rubbing or puddllng action, or both, across the same which causes thematerial along the seam' to be worked into a thoroughly commingled andstrongly united condition.

Referring to the drawing, the numeral lll designates a conveyor beltsupported by rotatable idler rolls l l, journaled in supporting framemembers l2. I3. The conveyor belt is also supported by driving pulleys(not shown). A slab or layer Il of tire tread and sidewall stockisrdelivered progressively to the belt l0 from a. suitable supply. Asecond slab or layer l of tread stock is fed onto the slab l5, as bymeans of a guide il. A pressure roller I8, preferably comprising conicalend portions 18a, I8b, is mounted above the belt l0, for rotation, inanti-friction bearings i9. te

,fitted in arms 2l, 22 ilxed to a shaft 23. Shaft 23 is journaled inside brackets, of which one is shown at 24 in Fig. 2, supported byframe-members l2, I3. A lever 28 is fixed to shaft 23 and is pivoted toa piston-rod 21 attached to a piston 28 of a double-acting huid-pressurecylinder 29, pivotally mounted, at 30 to one of theframe members. Thearrangement is such that roller I8 is forced toward the belt l0 and actsto press the slabs together but may be raised by reversal of the iiuidpressure supply to cylinder 29.

There is provided, for working themarginal zone of the joint between theslab portions l5 and IB, so as to intermingle and interlock thematerials thereof and seal the joint, a pair'of pud. dling tools 3|, 32having blunt and`preferably rounded ends 3 la. These toolsare-rotatablysu'w ported in the path of seams between the materials andare adapted to rub or knead the material at the seam and across the sameby frlctional engagement therewith. Each puddling tool is provided witha driving motor 33, 34. To support the puddling tool resiliently, asocket 35 is iixed to each motor shaft 38 and a chuck 31 for holding thetool is slidably mounted in the socket 35 for limited axial movementpermitted by a cross-pin 38 of the chuck 31 extending through a slot 3Sof the socket. A compression coil spring 4G encircles the shank of thechuck between the socket 35 and the chuck 31 to cushion end-movement ofthe puddler.

Each puddler motor is iixed to a slide 4i iitted in a bracket 42 alongwhich it may be adjusted by a screw 43 operable by a crank-handle 44 tomove it toward or from the slab. Each bracket 42 is rotatably adjustableon an axis perpendicular to its slideway to change its angular relationto the work, and for this purpose has a shank 45 rotatably journaled ina bracket, the two brackets being shown at 46, 46 in Fig. 1. A crampscrew 41 serves to lock the brackets 42 and 46 in any desiredadjustment.

Each bracket 46, 46' is adjustable in a direction across the belt I0 toadjust the apparatus to slabs of diilerent widths, and/for this purposea shaft 50 is rotatably mounted in bearings 5|, 52 fixed to the frame ofthe machine. Arms 53, i4, are iixed to shaft 50 at intervals and a shaft5B extends through aligned bearings in these arms so as parallel shaft50. Shaft 56 has right and left-handed threaded portions ill, at. Thelett bracket 46, as seen in Fig. l, is clamped to a threaded bushing 59which engages a threaded portion of shaft 56. The other bracket 46'directly engages the threads of shaft t. By turning shaft 56, the ,toolsmay be moved simultaneously toward and from each other. By turning thebushing E@ one tool may be adjusted independently. A lock screw E5@locks the left bracket t8 to its threaded bushing 59. A knurled knob @ililxed to shaft 56 facilitates turning of the shaft. The arrangement issuch that the tools may be adjusted to align them withthe work and fordiierent widths of work.

'lo raise and lower the tools with respect to the conveyor belt, as whenstarting a new slab therethrough, a bell-crank lever @Il is lined toshaft 5@ and has a handle 65 on its longer leg. its shorter leg has astop pin Gt slidable in an aperture therethrough and engageable withsockets G1 formed in a ange @il or bracket 5i. The arrangement ls suchthat by lifting the pin 635 the lever handle 65 may be moved to rotateshaft and raise or lower the tools with relation to the work..

The tools 3i and 32 are each mounted so as to rotate about an axis thatpreferably extends obliquely away from the longitudinal vertical centerplane of the work and ohliquely in the direction of feed. As the tool isrotated about its axis in the direction of the arrow in Figs. l, 2 and 6the portion of the rounded Vend face of the tool in contact with thework is caused to be wiped and pressed across the seam away from thecenter of the tread, which action, together with the movement of thework vpast the tool, causes the f lmeading or puddling of the materialofthe slab portions to unite the same intimately and progressively alongthe seam. While smooth rounded ends of the tools, as shownfor example atBia in Fig. 6,V have given good results, the end faces of the tools maybe knurled or otherwise roughened, if desired, for effecting a strongergrip on the material of the work.

Additional pressure rollers 1U, 1l are provided for rolling the seam ina direction of its length after it has passed the puddler tools. Each ofthese rollers is mounted for rotation about a pivot 12 on a bracket 13xed to a piston-rod 14 'of a fluid pressure cylinder 15. adjustablealong a'supporting bar 16 which extends across the conveyor, and issecured thereto by a screw 11. The wheel is mounted at an angle tothe-vertical so that its face isv parallel to the seamed margin of theslab. .When air under pressure is released, the roller 10 is raised by acoil spring 8| on piston rod 14. An air pipe IO-.connect's the cylindertoany suitable source of supply (not shown) l In the operation of theapparatus of the invention, slabs I5 and i6 of plastic material such asunvulcanized rubber composition are assembled in superimposed relationon the conveyor belt I0. As they are conveyed along the belt, the rolleril'bears on the top slab and presses the slabs together. Thereafter, thepuddler tools 3|,l 32 engage the margins ofthe slabs at the seams,

- the rotation of the tools causing them to engage the slab materialirictionally at one side of the seam and,I to drag, knit, or puddle itacross the seam, interlocking the two materials intimately andcompletelyl closing the seam against entrance of? dirt or moisture.

As the slab leavesl the puddler toolsit travels below the roller 10which rolls the puddled seam The cylinder l5 is material to an adjoiningbody o yieldable comme in a direction longitudinal of the slab, whichfurther compacts the material and makes for greater smoothness of thesurface.

The invention has been round useful especiallyr in the forming or treadslabs for tires where the imeading or puddling action is eective tomanipulate the material deeply below the exposed surface to eiect a goodunion of the zones below. The invention, however, may be usedadvantageously to seam plastic material for purposes other than tiretread slabs, where a closed, intimately united seam is desired. l

Variations may be made without departing from the scope of the inventionas it is defined by the following claims.

We claim:

l. The method of uniting a body of plastic material to an adjoining bodyor yieldable material, which method comprises working the material ofthe bodies together at the edge of first said body by wiping thesurfaces ci* 'the bodies in a direction .crosswise of said edge andalong the same.

2. The method of uniting a body of plastic terial whlchmethod comprisesworking the ma terial of the bodies together in the zone or the edge ofthe first said body by rotating the surface of a tool against thematerial in a direction across said edge and advancing the material topresent its edge progressively to the tool along said edge.

3. The method ofuniting a body of plastic material to an adjoining bodyof yieldable material which method comprises working the material of thebodies together in the zone of the edge of the first saidbodyby'rotating a rounded-end elongated tool about its longitudinal axiswhile the tool is held with its axis obliquely disposed with relation tothe surface of the material with its rounded-end surface contacting thematerial in a manner to wipe the rounded end surface ofthe tool acrosssaid edge and along said edge.

4. The method of uniting strips of plastic rubl v ber-like material insuperimposed relation. the

overlying strip having a beveled margin the edge of which is set backfrom the edge of the underlying strip, which method comprises advancingthe strips in superimposed relation, and working the material of saidstrips in the zone of said-edge of the rst said strip by rotating arounded-end elongated tool about its longitudinal axis while the tool isheld with its axis disposed obliquely away from the central zone of thestrips and'obliquely in the direction of advance of the strips, and withits rounded-end surface contacting the material in a manner to wipe'therounded end surface of the tool across said edge in the direction awayfrom the central zone of said strips as the strips are advanced.

5, The method' of uniting strips of plastic rubber-like material insuperixnposedrelation, the' overlying strip having beveled margins, theedges of which` are set back from the edges of the underlying strip,which method comprises advancing the strips in superimposed relation,and working-the material `of said strips in zones of the edges of therst' said strip by rotating roundedend elongated tools about ,theirlongitudinal axes while the'tools are held with their axes disposedobliquely away from the zones of the strips and obliquely "in thedirection of the advance of the stripsl and with their rounded-endsurfaces contacting the material in a manner to' wipe the rounded-endsurfaces of the tools across said edges in the directions away from thecentral zone of 8. The method of uniting adjoining bodies ciunvulcanized rubber-like material which com prises assembling the bodiesin4 overlapping relation, applying a blunt tool to the exposed sur,-face of one of said bodies at a position overlying the overlap, andmoving the tool in a direction to wipe a surface thereof crosswise ofvthe overlap and t0 depress and knead the material so as to Y.

manipulate the same throughout a depth including the zone of theoverlapping faces thereof.

9. Apparatus for uniting a body oi plastic mafA terial to an adjoiningbody of yieldable material which apparatus comprises a rounded-end tool,means for moving the tool in a wiping movement of its rounded-endagainst the material across the edge of the ilrst said body, and meansfor effecting relative movement of the material and said tool along saidedge.

10. Apparatus or uniting a body of plastic ma-v terial to an` adjoiningbody of yieldable material which apparatus comprises a rounded-end elongated tool, means for supporting said tol with its axis disposedobiiquely witli relation to the surface of the material and for rotatingthe tool about its longitudinal axis to wipe the roundedend thereofacross the edge of the tlrst said body, and means for eiecting relativemovement of the material and said tool along said edge.

1l. Apparatus for uniting strips of plastic rubber-like material insuperimposed relation with a beveled margin of the overlying strip setback from the edgeoi the underlying stripsaid apparatus comprising meansfor advancing the strips,

zone of the strips;

arounded-end elongated tool, and means for supportingsaid tool with itsaxis disposed obliquely away from the central zone of the strips andobliquely in the direction of advance of the strips and for rotating thetool aboutits axis -to wipe its rounded end across `sa'idbeveled margin.'l

v 12. Apparatus'for uniting strips of plastic-rubber-like material insuperimposed relation with beveled margins of the overlying strip setback from the edgeoi' the underlying strip-said apparatus .comprisingmeans for advancing the strips. a pair of rounded-end elongated tools,and means for supporting said tools with their axes disposed obliquelyaway from the central zone of the strips and obliquly in the directionof advances of the strips and for rotating the tools about their axes towipe their rounded-ends across'said beveled margins in the directionsaway from the central CHARLES w. LEGUruioN.'

.mmh YOUNG.

